Compostable v biodegradable
'Compostable' products, e.g. compostable kitchen caddy bags, are made from starch and vegetable oils. They will break down completely in the presence of oxygen and micro-organisms (fungi or bacteria) in a relatively short time frame leaving no physical residues (micro-plastics) or chemical residues harmful to plants or animals.
Look for the looped seedling logo or home compostable logo, the international certification symbols that verify a product's claim of compostability according to the Australian Standards.
You cannot put plastic bags or bags labelled 'degradable', 'biodegradable' or 'oxo-degradable' in your organics bin or home compost bin. Plastics labelled 'oxo-degradable' are merely plastics with additives to accelerate their breakdown when exposed to UV radiation or heat.
To find out what products and bioplastics are certified as compostable, visit the Australian Bioplastics Association. See Who is certified in Aus & NZ.
For more information read the Joint Discussion Paper of AORA and ABA entitled 'Certified Compostable Bioplastics'.